Integrative redescription of the Xerobiotus euxinus Pilato, Kiosya, Lisi, Inshina & Biserov, 2011 (Tardigrada: Eutardigrada: Macrobiotidae) population from Ukraine

Abstract

Using integrative taxonomy, we redescribe an eutardigrade Xerobiotus euxinus Pilato et al. 2011 based on material from the type locality and additional population from the Black Sea Biosphere Reserve in the south of Ukraine. Integrative redescription is based on morphological and morphometric data of animals and eggs from both phase contrast light microscopy (PCM), as well as, from scanning electron microscopy (SEM), and four DNA markers, three nuclear (18S rRNA, 28S rRNA, ITS-2) and one mitochondrial (COI). Originally, the species was described solely based on adults’ morphology. The uncorrected genetic distances indicated that X. euxinus is the most similar to X. gretae with a p-distance value of COI fragment. Morphologically, X. euxinus differs from all Xerobiotus taxa mainly by the shape of claws on legs IV, but also by some other morphological and morphometrical characters of eggs and animals.

Keywords

• DNA barcoding
• Eutardigrada
• Tardigrada
• taxonomy
• water bears